Incremental Optimization of Power Pads Based on Adjoint Network Sensitivity

Jairam S and Subir K Roy
SDTC, TI India


An adjoint network sensitivity based incremental power pad optimization approach is proposed. The power grid is formulated as a linear network of resistive elements. Sensitivity of power pads due to the grid elements is computed. An overall cost metric is then formulated in conjuction with IR drop. This metric is then used to refine a prior optimized source location incrementally, while meeting the IR Drop constraint. The power of the approach lies in its much reduced computational complexity. Results are presented in terms of sensitivity computations before and after the incremental refinements to demonstrate the relative in-sensitivity of the power pads towards the grid elements.